Problem: Solve for $x$ : $4x - 3 = 9x + 7$
Explanation: Subtract $4x$ from both sides: $(4x - 3) - 4x = (9x + 7) - 4x$ $-3 = 5x + 7$ Subtract $7$ from both sides: $-3 - 7 = (5x + 7) - 7$ $-10 = 5x$ Divide both sides by $5$ $\dfrac{-10}{5} = \dfrac{5x}{5}$ Simplify. $-2 = x$